Hypodermic syringe



June 13, 1967 o. T. ELLSWORTH 3,325,051

HYPODERMIC SYHINGE Filed Sept. 1, 1965 irrae/viKs United States PatentCalif.

Filed Sept. 1, 1965, Ser. No. 484,294 6 Claims. (Cl. 222386) Myinvention relates to medical appliances primarily for human use and isespecially concerned with a hypodermic syringe that can be utilizedeither for the introduction or withdrawal of material to or from thehuman body.

While syringes of various sorts are utilized and have been proposed forintroducing materials either subcutaneously or intravenously and alsohave been utilized for withdrawing various fluids from the body, thisoperation sometimes requires careful use of two hands, particularly forfluid withdrawal.

It is therefore an object of the invention to provide a syringe whichcan easily be used for introducing or withdrawing fluid material to orfrom the human body.

Another object of the invention is to provide a hypodermic syringe thatcan readily be operated by but one hand of the user..

Another object of the invention is to provide a hypodermic syringe whichgenerally is of standard construction but which has in addition meansfor adapting it to one-hand use for either direction of operation.

Another object of the invention is to provide a hypodermic syringe theoperation of which is visually indicated.

Another object of the invention is to provide a hypodermic syringe whichgenerally is an improvement over hypodermic syringes presentlyavailable.

Other objects together with the foregoing are attained in the embodimentof the invention described in the accompanying description andillustrated in the accompanying drawings, in which:

FIGURE 1 is a view generally in side elevation showing the syringe ofthe invention as utilized with one particular hand grip;

FIGURE 2 is a plan, portions being broken away, showing the hypodermicsyringe of the invention;

FIGURE 3 is a cross section, the plane of which is indicated by the line3-3 of FIGURE 2;

FIGURE 4 is an end elevation, the view being indicated by the line 4-4of FIGURE 2; and

FIGURE 5 is a cross section, the plane of which is indicated by the line5-5 of FIGURE 2.

While the hypodermic syringe can be embodied in a number of differentways, it has successfully been incorporated and used as illustratedherein. In this embodiment, the syringe includes a generally circularcylindrical barrel 6 made of any suitable material. This customarily isa plastic material that can readily be sterilized or is sufficientlycheap to be disposed of after single use. The material of the barrel 16is somtimes made completely transparent, but in accordance with theinvention need not be so and can be of an opaque material.

One end of the barrel 6 is provided with a connector 7 to receive astandard hypodermic needle 8 in the usual way, while the other end ofthe barrel 6 is provided with an outstanding terminal flange 9 includingtabs 11 and 12 arranged so that, if desired, they can act as stops forthe adjacent fingers of a users hand. The barrel 6 is arranged toreceive a plunger 13 which reciprocates therein along the axis of thebarrel. The plunger is a composite structure and preferably includes apiston head 14 having a pair of sealing rims 16 and 17 thereon. The head14 is joined to a piston rod 18 preferably comprised of radiallyarranged Patented June 13, 1967 plates acting in part as guides againstthe internal walls of the cylinder and terminating in a transversedisk-like head 19.

The arrangement as so far described can be utilized in the customaryfashion of a hypodermic syringe in that the user by placing his fingersadjacent the tabs 11 and 12 and his thumb against the head 19 canreadily depress the plunger or reciprocate it inwardly with respect tothe barrel.

In accordance with the invention, there is provided means for assistingin withdrawing the plunger from the barrel. This means includes a slide21 conveniently fabricated of plastic and arranged to overlie the barrel6. The slide 21 is preferably arcuate in cross section concentric withthe barrel and at one end is provided with notches 22 and 23 tointerengage with a correspondingly notched portion of the head 19. Theslide is also guided by sliding engagement with lugs 24 and 26 formed aspart of the flange 9. In this way, the slide and the plunger are securedtogether for reciprocatory motion in unison and in both directions.

Preferably, the slide 21 has a roughened portion 27 for betterfrictional engagement with the thumb of a user operating the device. Theslide 21 carries an indicating line or carries a terminal surface 28which coincides substantially with the end of the plunger 13, so that anexterior observation of the end of the slide is an indication of theinternal, end position of the plunger. To assist this visual indication,the barrel contains indicia 29 preferably in the form of the customarygraduations indicating the content of the barrel in cubic centimeters.

In the use of this device for ordinary injection, the syringe can beused in the customary way by pressure against the head 19, or thesyringe can be utilized by grasping the barrel 6 in the fingers with theusers thumb on the roughened portion 27. By movement of the thumb, theplunger can then be moved inwardly or outwardly with equal facility, theamount of motion being observed by gauging the end of the slide againstthe indicia 29.

As an alternate manner of using the syringe, it can be grasped like apencil with the barrel between the thumb and second finger of the userand the slide engaged by the index finger of the user. This graspingposition also facilitates both inward and outward movement of theplunger. In the claims herein, reference is had to the thumb of the userengaging the slide, but it is to be understood that such operation ismerely the usually preferred one and that some may prefer to utilize theso-called pencil grip with the index finger in contact with theroughened portion of the slide.

With this hypodermic syringe, it has been found that both injections andextractions can readily be accomplished with but one hand and in anaccurate and controlled fashion. The mechanism is such that it canreadily be disassembled if necessary by completely withdrawing theplunger and the slide from engagement with the barrel and the flange 9,and the parts can be sterilized if so desired.

What is claimed is:

1. A hypodermic syringe comprising a cylindrical barrel adapted to begrasped by the fingers of a users hand, a plunger reciprocable in saidbarrel, a slide connected to said plunger and overlying said barrel, andmeans on said slide adapted to be engaged by the thumb of said usershand for moving said slide axially in both directions to move saidplunger in said barrel.

2. In a hypodermic syringe including a cylindrical barrel adapted to begrasped by the fingers of a users hand having a plunger reciprocabletherein, a slide overlying said barrel and connected to said plunger,and means on said slide adapted to be engaged by the thumb of said usershand for moving said slide axially in both directions to move saidplunger in said barrel.

3. A hypodermic syringe as in claim 2 in which said slide is attached tosaid plunger at one end of said slide and in which said thumb-engagingmeans is a rough portion of said slide at the other end thereof.

4. A hypodermic syringe as in claim 1 having means on said barrel forresisting rotation of said slide.

5. A hypodermic syringe as in claim 1 in which said slide is attached tosaid plunger at one end of said slide and in which said thumb-engagingmeans is a rough portion of said slide at the other end thereof.

4 6. A hypodermic syringe as in claim 2 having means on said barrel forresisting rotation of said slide.

References Cited UNITED STATES PATENTS 14,734 4/1856 Palmer 222-50 X691,515 1/1902 Wieberg 222-386 X 2,198,666 4/1940 Gruskin 222-47 X3,253,592 5/1966 Von Pechmann 222-386 X 10 ROBERT B. REEVES, PrimaryExaminer.

N. L. STACK, Assistant Examiner.

1. A HYPODERMIC SYRINGE COMPRISING A CYLINDRICAL BARREL ADAPTED TO BEGRASPED BY THE FINGERS OF A USER''S HAND, A PLUNGER RECIPROCABLE IN SAIDBARREL, A SLIDE CONNECTED TO SAID PLUNGER AND OVERLYING SAID BARREL, ANDMEANS ON SAID SLIDE ADAPTED TO BE ENGAGED BY THE THUMB OF SAID USER''SHAND FOR MOVING SAID SLIDE AXIALLY IN BOTH DIRECTIONS TO MOVE SAIDPLUNGER IN SAID BARREL.